Well Ordinance Update

In 2014, the state Legislature took action to stop unsustainable groundwater usage. The Sustainable Groundwater Management Act required local agencies in 94 of California’s 515 groundwater basins to create plans to bring their areas into balanced levels of groundwater pumping and recharge by the year 2042. Sonoma County has three groundwater sustainability agencies that developed groundwater sustainability plans for the Santa Rosa Plain, Petaluma Valley and Sonoma Valley.

The County of Sonoma will collaborate with groundwater sustainability agencies as these agencies implement their groundwater sustainability plans.

The Board of Supervisors, on April 18, 2023, gave final approval to a proposal to amend the County’s existing Well Ordinance to incorporate a Public Trust Analysis. The changes to the Well Ordinance require basic water conservation measures for all new wells and more stringent water conservation measures and review for wells using greater than two (2) acre-feet of water per year if located in the area referred to as the Public Trust Review Area.

The review area is where public trust resources are sensitive to reduced streamflow due to groundwater pumping. Streamflow is a term that refers to the measure of the rate of water carried in rivers and streams. In reviewing well permits within the Public Trust Review Area, water conservation plans and limits on vineyard and orchard irrigation would apply. In addition, new wells that are increasing the total groundwater use of the site beyond two (2) acre-feet per year could only be issued if there is a written finding by county staff that the permit would not have an adverse impact on public trust resources in rivers and streams.

The Board of Supervisors on April 18 is scheduled to review and give final approval to a proposal to amend the county’s existing well ordinance to incorporate a public trust analysis. The changes to the well ordinance would require basic water conservation measures for all new wells and more stringent water conservation measures and review for wells using greater than 2 acre-feet of water per year if located in the area referred to as the Public Trust Review Area. The review area is where public trust resources are sensitive to reduced streamflow due to groundwater pumping. Streamflow is a term that refers to the measure of the rate of water carried in rivers and streams. In reviewing well permits within the Public Trust Review Area, water conservation plans and limits on vineyard and orchard irrigation would apply. In addition, new wells that are increasing the total groundwater use of the site beyond 2 acre-feet per year could only be issued if there is a written finding by county staff that the permit would not have an adverse impact on public trust resources in rivers and streams.

The definition may vary depending on flow and habitat conditions of that stream. But in general, it would be defined as a significant reduction to instream flows that support salmonids.

Streamflow is a term that refers to the measure of the rate of water carried in rivers and streams. Should Coho-bearing streams see cumulative reductions in streamflows of 10 percent, and Steelhead-bearing streams see reductions of 20 percent, that would meet a preliminary threshold for an adverse effect.

An alternative standard could be adopted by the Board of Supervisors after public hearing, public comment and written findings.

There are a number of feasible mitigation measures, including water conservation, enhanced groundwater recharge, reductions in surface water diversions, flow augmentation, forbearance of groundwater pumping and enforceable offsets of existing groundwater uses.

No meters will be required on any existing wells. No meters will be required on new wells that extract less than 2 acre-feet per year for residential purposes. Installation of water meters will be required on most new wells that serve parcels with non-residential and mixed-use purposes. For wells where a meter is required, meter readings must be recorded monthly and reported to the county once a year.

To determine which applications would require meter installation, Permit Sonoma would evaluate the land uses on a parcel using methods applied by local groundwater sustainability agencies in their rate and fee studies. Employing these methods, most residential properties are projected to extract less than 2 acre-feet annually, a figure used with the state’s drought executive order and by groundwater sustainability agencies. If the parcel is used for residential occupancy with the normal accessory structures (ADU, guest house, pool house, art studio, garden, etc.), no meter would be required. Parcels with mixed uses (domestic and commercial agriculture or domestic and commercial) will be subject to metering.

Basic water conservation requirements including a leak and water conservation self-audit, and limits on existing lawns to less than 2,500 square feet, will apply to all permits for private wells. In the Public Trust Review Area of the county, additional review and documentation may apply if the well is for a higher-water-use site. Some permit applications may need to be denied to protect public trust resources, while others may be required to take mitigation measures to offset their impact.

The National Marine Fisheries Service and other resource agencies have found pumping groundwater can lower water levels in underground aquifers. This, in turn, can significantly lower summer streamflows in nearby creeks. Many of these creeks are inhabited by endangered Coho salmon, which can become trapped in small pools and die when streamflows subside over summer.

Sonoma County has roughly 40,000 water wells, the most per capita of any county in California. Approximately 23,000 parcels in Sonoma County rely on groundwater from a private well for their primary water supply.

Permit Sonoma, also known as the Permit and Resource Management Department, received an average of 283 water well permit applications annually between 2017 and 2021.

It is estimated the number of water well permits potentially subject to the proposed public trust evaluation is between 5 and 15 per year.

The California Coastkeeper Alliance filed a first lawsuit against the County of Sonoma in July 2021 to force the County to comply with the public trust doctrine when issuing well permits. The litigation settled following the Board of Supervisors Hearing on October 4, 2022, resulting in a temporary moratorium on well permitting and the County’s commencement of the public process to amend the well ordinance.

The California Coastkeeper Alliance and the Russian Riverkeeper filed a second lawsuit against the County of Sonoma in May 2023 that contends that (1) the amended well ordinance does not meet obligations under the public trust doctrine and that (2) the Ordinance adoption was not CEQA exempt. Litigation is ongoing.